Chemicals such as pharmaceuticals and agrichemicals are generally required to have water solubility because of the nature of their use. One of the means of improving the water solubility of those chemicals that have been proposed in recent years is by including them in cyclodextrin.
However, because of the limited solubility of cyclodextrin in water, the cyclodextrin inclusion compounds have had the problem that their water solubility is still insufficient for practical applications. Under these circumstances, efforts have been made to improve the solubility of cyclodextrin in water by various methods such as methylating, hydroxyethylating or hydroxypropylating cyclodextrin, or synthesizing polymers crosslinked with epichlorohydrin, but no satisfactory results have yet been achieved.
Therefore, an object of the present invention is to provide cyclodextrin derivatives having extremely high solubility in water.